Field of the Invention
This invention relates to check valves, and relates more specifically to a check valve for medical usage.
Description of the Background Art
Presently, there are many types of check valves which are designed to control the one-way flow of a fluid therethrough. One common type of check valve comprises a valve element, such as a ball or spring biased valve stem, reciprocatingly positioned within a valve body providing a fluid passageway. The flow of fluid in one direction through the valve body is permitted upon displacement of the stem as it flows around the valve stem to exit the valve body. In the opposite direction, however, the fluid pressure along with the spring forces the valve stem against a valve seat, thereby inhibiting, or checking the flow of fluid therethrough. In this manner, this type of check valve effectively provides that fluid can flow only in one direction through the check valve. An example of this type of valve is found in U.S. Pat. No. 5,349,984, the disclosure of which is hereby incorporated by reference herein.
Check valves employing an elastomeric stem without the use of a spring are described in U.S. Pat. No. 3,831,629, the disclosure of which is hereby incorporated by reference herein. Other check valves employing umbrella or disk-like elastomeric elements are described in the following U.S. Pat. Nos. 5,992,462; 4,499,916 and 4,369,812, the disclosures of which are hereby incorporated by reference herein. Some check valves employ elastically deformable diaphragm-like elements as described in U.S. Pat. No. 6,390,120, the disclosure of which is hereby incorporated by reference herein. Another check valve employing conical or hollow elastomeric elements where fluid flow is arranged to pass through the element itself is described in U.S. Pat. Nos. 5,573,516 and 5,746,414, the disclosures of which are hereby incorporated by reference herein. Some of the designs described above allow for bi-directional fluid flow if accessed by the appropriate connector such as a luer fitting commonly used in the medical fluid delivery field.
More contemporary check valves are reflected in U.S. Pat. Nos. 7,296,782 and 7,641,174 entitled “Dome Check Valve”, the disclosures of which are hereby incorporated by reference herein. The present invention represents an improvement over such dome check valves to increase the operation of the valve at high pressures.
Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the check valve art.
Another object of this invention is to provide a valve that seals itself to restrict fluid flow at very high back pressure on the order of about 1200 psi.
Another object of this invention is to provide a valve that includes a valve element made from a dome-like shaped elastomeric material which seals in its at-rest position occluding fluid flow in both directions.
Another object of this invention is to provide a valve including a dome-shaped elastomeric valve element that is constructed in such a way to be deflectable, such as being activated by the external device such as a male luer whereupon the valve is cracked open to become a two-way valve allowing flow in both directions.
Another object of this invention is to provide a valve having a valve element that is self-aligning.
Another object of this invention is to provide a valve having a valve element is self-supporting and when assembled in the valve, exerts a predetermined pressure against the valve seat thus sealing the valve, the valve element deflecting at the center after pressure rises over the cracking pressure or by being accessed by a syringe or other device, thus opening the bi-directional flow path.
Another object of this invention is to provide a valve having a dome-shaped valve element wherein the dome includes cut-outs for additional fluid flow, thereby streamlining flow while reducing the potential for air entrapment.
Another object of this invention is to provide a valve having a dome-shaped valve element having a thickened concave undersurface and thickened support legs to significantly increase the resistance to high backpressures, while also minimizing potential air entrapment that might otherwise occur underneath the prior art dome check valves noted above.
The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.